Vertically aligned polymer microfibril array for self-powered sensing

Abstract

Triboelectric sensor (i.e., triboelectric nanogenerator, TENG) has attracted increasing attention in recent years, owing to its unique superiorities such as less energy consumption, versatile material options and diversified architectures. In order to enhance sensitivity and signal to noise ratio (SNR) of triboelectric sensor, many micro/nano-structured tribo-layer (e.g., vertically aligned microfibril array) have been developed for this purpose. However, it is challenged to fabricate low-cost and robust tribo-layer with vertically aligned microfibril array by an efficient and environmentally friendly method. In this work, high-density polyethylene (HDPE) bundle containing oriented microfibrils was efficiently fabricated by extrusion molding, and it can be transversely sliced into microchips. After leaching, vertically aligned HDPE microfibrils array (HMA) were obtained from such microchips, which can be used as tribo-layer of triboelectric sensor (HMA-TES). The as-prepared HMA-TES shows decent sensitivity (5.8 V/N, i.e., 3.4 V/kPa) during touch sensing. Meanwhile, HMA-TES consisting of 8×8 HMA arrays shows decent output performance, successfully driving some microelectronic devices (e.g., LEDs and electronic meter). Furthermore, in virtue of Internet of Things (IoT), a touch sensing system was developed to realize human-machine interaction (HMI). This work proposes an efficient and environmentally friendly method for fabricating sensitive and robust triboelectric sensor, opening a new pathway to develop self-powered sensor following the concept of thermoplastic “functionalized” processing.